Crankshaft grinder



p 1938- v E. FUGLIE ET AL 2,130,003

CRANKSHAFT GRINDER Filed April 30, 1938. 2 Sheets-Sheet 1 Inventor; ,5 J21 0. 0e e #5 A iomeys CRANKSHAFT GRINDER Filed April so, 1958 2 Sheets-Sheet 2 76 Inventors E //'e 0. OKs/kins A itomeys Patented Sept. 13, 1938 UNITED STATES PATENT OFFICE CRANKSHAFT GRINDER Elmer Fuglie and Ore Oelkers, Mazeppa, Minn.

Application April 30, 1938, Serial No. 205,361

3 Claims.

' character particularly adapted for grinding or truing worn crank shafts.

An object of the present invention is to provvide a device of this character which is to be used for grinding or truing a crank shaft without requiring removal of the shaft from the engine block.

A further object of the invention is to provide a grinder having an abrading element associated therewith for contact with the shaft for grinding or truing the same, together with means for rotating the abrading element and also-for oscillating the abrading element so that it will move back and forth parallel to the axis of the shaft to insure a proper grinding of the throw for the fag length of the throw to insure perfect even grinding thereof.

The invention together with its objects and advantages will be best understood from a study of the following description taken in connection with the accompanying drawings wherein:--- a Figure 1 is an elevational view illustrating the application of the invention,

Figure 2 is a vertical sectional view illustrating the application of the invention,

Figure 3 is a bottom plan view showing an eccentric arm, and

Figure 4 is a top plan view of a wheel hereinafter more fully referred to.

Referring to the drawings by reference numerals it will be seen that in accordance with the present invention the improved grinding tool comprises a rod 5 formed at one end with an integral substantially circular split head 6 that is adapted. to be disposed concentric to the throw 1 of an automobile crank shaft 8 as clearly shown in Figure 2.

The head 6 includes a relatively fixed section 9 and a movable section l0 hinged to the fixed section as at l I.

The sections 9 and III of the head are provided with inserts l2 that are secured at the desired position on the sections of the head through the medium of adjusting screws l3. The inserts l2 are preferably of steel and have bearing contact with the throw 1 of the crank shaft as shown in Figure 2.

Also mounted on the shaft 5 to oscillate or swing back and forth relative to the shaft 5 as an The lower portion of the casting I4 is hollowed out to provide a housing l8.for an electric motor l9.

Also the casting I 4 is provided with vertical aligned bearings 20, 2| that accommodate one end of the armature shaft 22 of motor l9. On the upper terminal of said end of armature shaft 22 is a grinding or abrading disk 23 that has peripheral contact with the throw I of the crank shaft in a manner shown in Figure 2. In this connection it will be noted that one of the inserts l2 has contact with the throw 1 at a point substantially diametrically opposite to the point of contact of the abrading wheel 23 with said throw 1.

Secured to the lower end of the casting It through the medium of screws or other fastening elements 24 is a gear case 25 that at one end is provided with a bearing 26 to accommodate the shaft 5.

The armature shaft 22 of the motor has an end 22a thereof that extends through the gear case 25, gear. case 25 having a removable bottom plate 26 as shown.

On the shaft end 22 and arranged within the gear case 25 is a worm (see Fig. 2) 21 that is in constant mesh with a worm wheel 28 on a shaft 29 journaled in bearings 30 suitably provided therefor within the gear case 25.

Also journaled within the gear case 25 is a stub shaft 3| and intermediate its ends the shaft 3| is provided with a gear wheel 32 arranged within the case 25 and in mesh with a gear wheel 33 provided on the shaft 29.

On the lower end of the shaft 3| and disposed exteriorly of the case 25 is an eccentric wheel 34 that is provided, as shown in Figure 4, with a plurality-of openings 35 with a selected one of which is adapted to be engaged an eccentric pin 36, pin 36 being engaged with a selected opening 35 as determined by the length of the throw of the crank shaft being ground.

Further in accordance with the present invention there is provided an eccentric arm 31 that at one end is formed integral with a split loopshaped member 38. At the end formed by the split therein the member 38 is provided with opposed lugs 39-. Lugs 39 have their opposed faces provided with'threaded notches to accommodate the threaded end sections 40 of the shaft 5 as will be clear from a study of Figures 2 and 3. Lugs 39 are drawn into positive engagement with the threaded section All of the shaft 5 through the medium of bolt and nut means 4 I.

- The eccentric arm 31 is provided with an clanwith the throw 1 of the crank shaft.

gated longitudinal slot 42 which accommodates the eccentric pin 36 as shown in Figure 2.

The aforementioned threaded portion 40 of shaft 5'is squared as shown and at the corners thereof is provided with threads whereby to accommodate a nut 43, through the medium of which the device may be raised and lowered as found desirable.

From the above it will be seen that in operation shaft 22 is driven from the motor I6 to revolve the disk 23 while the same is in contact Obviously during the grinding thereof the crank shaft is slowly rotated so that all portions of the periphery of the throw 1 will be engaged by the disk 23 for the grinding and truing thereof.

Also drive of the shaft 22 is transmitted through'gearing 21,28, shaft 29, gearing 33, 32, to the eccentric wheel 34 and through the medium of the eccentric wheel 34, eccentric pin 36 and eccentric arm 31, casting I4 is caused to oscillate or rock back and forth on the shaft 6 thus causing the disk 23, during the grinding operation to move back and forth longitudinally with respect to the throw 1 of the crank shaft thus insuring a grinding of the throw of the shaft for the full length of the throw. Obviously, the length of the throw I will determine which hole 35 in the eccentric disk 34 will be used for mounting the pin 36 on said eccentric wheel.

Also to insure proper contact of the wheel 23 with the throw I there is housed within the gear case 25 a coil spring 38 that is interposed between the cover plate 26 and the gear 21 and acts to normally urge the shaft 22 and associated parts upwardly to engage the wheel 23 with the throw 1.

Also on the lower end of the shaft end 2211. are threaded stop nuts 44, 45 as clearly shown in Figure 2. Of these nuts, nuts 44 may be adjusted to one one-thousandth of an inch and when threaded home into contact with the case 25 will I bridges the hinge II and has one end bearing on thereto, a

the fixed part 9 of head 6 and a second end bearing on the hinged part IU of said head. The tension of the spring 4| is regulated through the medium of a suitable screw 42.

It is thought that a clear understanding of the construction, operation, utility and advantages of a crank shaft grinding tool embodying the features of the present invention will be had without a more detailed description.

Having thus described the invention what is claimed as new is:--

1. A machine for grinding an automobile crank shaft, and embodying a shaft provided at one end with a head adapted to be disposed concentric to the throw of a crank shaft for suspending said shaft from the crank shaft, means mounted on the head-equipped shaft for oscillatory movement relative to said head-equipped shaft, said means including an abrasive element arranged to have contact with the throw of the crank shaft and mechanism for driving said abrasive element and for oscillating said means whereby said abrasive element is caused to move back and forth lengthwise of the throw of the crank shaft during the grinding operation.

2. A tool for grinding automobile crank shafts comprising a shaft provided atone end with a head adapted to be disposed concentric to the throw of the crank shaft, a casting mounted on the shaft of the grinding tool to oscillate relative power-driven abrasive element mounted on said casting and arranged to contact the throw of the crank shaft, and power means for driving said abrasive element and for causing said casting to oscillate on the shaft of the tool.

3. In a tool for grinding crank shafts, a shaft member provided at one end with a head adapted to be disposed concentric to the throw of a crank shaft, a motor housing mounted on the shaft of the tool to oscillate relative to the tool shaft, an

, electric motor in said housing and having a shaft shaft, an abrasive element on said end of themotor shaft for contact with the throw of the crank shaft, and eccentric means driven from the shaft of said motor and connected with the shaft of the tool for causing said motor housing to oscillate when the motor is running.

EIMER FUGLIE. ORE OELKERS. 

